Скачать с ютуб Mini geared stepper motor test and teardown. в хорошем качестве

Mini geared stepper motor test and teardown.

The little stepper motors featured in the video are readily available on ebay for just £1 (about $1.50 USD). They also have matching drivers which are just a simple circuit based on a ULN2003 seven stage darlington driver. The driver board takes the logic level signals from an Arduino or microcontroller and buffers them up to allow switching of up to 500mA per channel. The motors have five connections. A common positive and four windings that when pulled to the negative rail in sequence cause the output of the motor to rotate. The motor is geared for higher resolution and torque, and also has a slip-clutch that prevents damage if the output is forced round or jammed. These motors seem to be used in air conditioning units to give positional control and sweep options on the air outlet vents. They generally just wind in one direction at start up, slipping at the end of travel until the time taken to reset from a fully open to closed position has been achieved. This means that no matter where the louvre started, it will always be in a known open or closed position. And from there the controller only needs to move it back and forth with known numbers of pulses to position it anywhere or even pan it back and forth. The motor in this video is rated for 5V and draws just 120mA per winding. To test it I wrote a small machine code (assembler) routine for a PIC12F629 microcontroller that had some simple loops and delays to provide the required positioning pulses. It winds the vent open for a fixed length of time and then oscillates it back and forth with a short delay at each end of the travel.